Nazov: Mass loading of quiescent prominences from multi-spectral
observations
Prezentujuci autor: Pavol Schwartz
Spoluautori: P. Heinzel, P. Kotrc, U. Anzer and Yu. A. Kupryakov
Abstrakt:
The total mass and plasma density of a quiescent prominence is an
importrant quantity for its reliable modelling. We estimated the total
mass of prominences from multi-spectral data: EUV observations in
coronal and chromospheric lines, observations in the soft X-rays and
H_alpha spectra. The total mass is obtained by integration of the
column density of the hydrogen and helium plasma over the whole
prominence area. Column density is calculated using the method of
Heinzel et al. (2008) based on two assumptions: First, depression
of EUV coronal radiation at a prominence is caused by two mechanisms
acting at the same time -- absorption in resonance continua of H and He
and the coronal emissivity blocking, while absorption of X-ray radiation
is negligible. Second asumption is the fact that only at the prominence
both mechanisms act on EUV radiation. In cavity surrounding the prominence,
only blocking is responsible for depression. Then, comparing intensities
of coronal EUV lines and X-ray brightness in prominence and cavity the
optical thickness of prominence hydrogen plasma and subsequently hydrogen
column density is estimated. H_alpha intensities are used for estimations
of the hydrogen ionization degree, a very important parameter for correct
determinations of the prominence mass. We created a semi-automatic code
based on the method, capable of analyzing a large aumount of prominence
observations. Moreover, we improved the method by taking into account
non-symmetrical distributions of the coronal X-ray and EUV emissivity in
front and behind the prominence. Our aim is to observe a large number of
quiescent prominences, in order to make a statistics of their total masses.
From May through June 2011, a multi-spectral observing campaign of quiescent
prominences took place. EUV and X-ray filterogramns were taken by the AIA
instrument on board of SDO and by XRT telescope on board of Hinode satellite,
respectivelly. H_alpha spectra were obtained by horizontal spectrographs of
the Ondrejov observatory.